This invention relates to a method for transferring and displaying data pages at a station connected to a network by a low-speed connection. In particular, this invention relates to a method for reducing the delay between the time a data page is requested and the time the page is displayed.
In data networks such as the Internet, data is stored on servers interconnected by high-speed connections. Such networks support protocols, such as the Hypertext Transfer Protocol (“HTTP”) used in the popular World Wide Web portion of the Internet, in which data is transmitted to users in a format known as a “page.” Under the HTTP protocol, the user interface software (known as a “browser”) cannot begin to display a page until a significant portion of the page has been received, and clearly cannot fully display the page until the entire page has been received. The resulting delays are referred to as “latency.”
Unfortunately, many Internet users are connected to the Internet by relatively slow connections using a modem and a standard telephone line. Even the fastest commercially available telephone modems are limited to speeds of 28.8 kilobits per second (“kbps”), or in some cases 33.6 kbps. This limits the speed at which a World Wide Web page can be transmitted to a user and displayed by the user's browser. In addition, heavy user traffic, particularly heavy access by other users to the same server, also slow down the apparent speed of the World Wide Web. As a result, many users complain about the slow speed of the Internet in general, and the World Wide Web in particular. In fact, much of the latency perceived by users is the result of their relatively slow connection to, and heavy traffic on, what inherently ought to be a very fast network.
Currently available browser software makes some attempts to eliminate delays in receiving World Wide Web pages. For example, most browsers will store received pages in a disk cache. If the user asks for a page within a short time after having asked for it previously, the browser will retrieve the page from the cache. However, under the HTTP protocol, certain World Wide Web pages may not be cached, such as those that are dynamically generated. Therefore, current caching techniques are of limited usefulness in solving the latency problem.
It would be desirable to be able to reduce the perceived delays encountered in transmitting data pages from a relatively fast network to a user connected to the network by a relatively slow connection.
It would also be desirable to be able to make better use of the caching capabilities of browsers.